Compact design for combination of an electrical circuit with a segmented electrode development roll

ABSTRACT

A compact design for the electronic circuits to provide electrical contact to a SED roll of a segmented electrode development unit is provided. In this invention, all the required high voltage and low voltage circuitry is placed on a printed flexible circuit which is folded and rolled into a cylindrical circuit to be connected to the SED roll. The flexible printed circuit has a plurality of output terminals each of which will be connected to one of the electrodes of the SED roll.

BACKGROUND OF THE INVENTION

This invention relates generally to a Segmented Electrode Development(SED) unit of a printing system and more particularly concerns a compactdesign for the electrical connection of a SED roll of a SED unit.

In general, the process of electrophotographic printing includescharging a photoreceptor to a substantially uniform potential so as tosensitize its photoconductive surface. Referring to FIG. 1, there isshown a prior art photoreceptor 10. Usually, a scanning light beam 12scans a scan line 14 on a photoreceptor 10. The photoreceptor 10 rotatesand as a result, the scanning light beam scans consecutive scan lines 14to discharge the photoreceptor 10 and transfer an image onto thephotoreceptor. The image on the photoreceptor 10, which is anelectrostatic image, is called a latent image. Once a latent image iscreated on each scan line, toner has to be placed on each individualscan line 14 to be transferred onto a sheet of paper and then heated topermanently fuse to the sheet of papaer.

One method used for transferring the toner onto the latent image, knownas Segmented Electrode Development (SED), uses a SED roll 16. Referringto FIG. 2, there is shown a magnified view of the SED roll 16 of FIG. 1.Referring to both FIGS. 1 and 2, SED roll 16 is a cylindrical memberwhich is placed along the photoreceptor 10 and has a plurality ofelectrodes 18 that are closely spaced along the SED roll 10.

As the photoreceptor 10 and the SED roll 16 rotate, at any given time,one or multiple electrodes 18 which have the closest distance to thephotoreceptor 10 will be activated. The activated electrodes 18 generatea toner cloud 19 along their length in a development region near thephotoreceptor. The latent image on each scan line 14 has opposite chargeto the charge of the toner in the toner cloud 19. Electrostatic fieldsgenerated by the latent image attract toner from the toner cloud 19 todevelop the latent image.

In order to activate a selected number of the electrode 18, a carbonelectrical brush 20 is used. Electrical brush 20 contacts a portion ofthe SED roll 16. As the SED roll 16 rotates, different electrodes 18come in contact with the electrical brush 20.

Electrical brush 20 is not a reliable contact to the electrodes 18. Whenthe electrical brush 20, which has a high voltage of about 1000 volts,connects to each electrode 18 or disconnects from each electrode 18 aphenomenon called "arcing" happens. The connection and disconnection ofa 1000 volts to and from an electrode cause large sparks. Since thereare plurality of electrodes 18, for example 312 electrodes, on a SEDroll 16 and the SED roll 16 rotates at a speed in the range of 400 to600 rpm, the electrical brush 20 withstands an enormous number ofsparks,but gradually, the sparks cause the electrical brush 20 andelectrodes 18 to wear off. As a result, the electrical brush 20 has ashort life span.

The object of this invention is to provide a reliable solution for theelectrical connection to a SED roll.

SUMMARY OF THE INVENTION

The present invention is directed to a compact design for the electroniccircuits of a Segmented Electrode Development (SED) unit. In thisinvention, a printed flexible circuit is used to hold the requiredcircuitry. The printed flexible circuit is folded and rolled to create acylindrical circuit to be attached to a SED roll of the SED unit. Thecylindrical circuit has a plurality of output terminals each of whichwill be connected to an electrode of a SED roll and a plurality of inputterminals to receive the required power to the electronic circuits.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a prior art photoreceptor along with a SED roll;

FIG. 2 shows a magnified view of the SED roll of FIG. 1;

FIG. 3 shows a printed flexible circuit with all the required circuitryto provide electrical connection to a SED roll;

FIG. 4 shows the flexible circuit of FIG. 3 without the electricalcircuits and connections;

FIG. 5 shows the process of rolling the flexible circuit of FIG. 3;

FIG. 6 shows the flexible circuit of FIG. 3 rolled into a cylindricalcircuit;

FIG. 7 shows the cylindrical circuit of FIG. 6 being connected to a SEDroll;

FIG. 8 shows a spool which provides a sturdy connection between a SEDroll and the cylindrical circuit of FIG. 6;

FIG. 9 shows how the spool of FIG. 7 holds the cylindrical circuit ofFIG. 6 to be connected to a SED roll;

FIG. 10 shows the assembly of FIG. 9 along with the electrical brushesand electrical pin contacts;

FIG. 11 shows an alternative embodiment of this invention;

FIG. 12 shows the flexible circuit of FIG. 11 being folded, wrappedaround a spool (not shown) and being connected to a SED roll;

FIG. 13 shows a slip ring barrel;

FIG. 14 shows a cross sectional view of FIG. 13 along plane 14;

FIG. 15 there is shown the slip ring barrel being slid over thecylindrical circuit of FIG. 12; and

FIG. 16 shows the slip ring barrel of FIG. 15 being completely slid overthe cylindrical circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 3, there is shown an electrical connection 30 of thisinvention. In FIG. 3, there is shown a one piece printed flexiblecircuit 32, which has a shape that can be defined as four distinctsections A, B, C and D. Referring to FIG. 4, there is shown the printedflexible circuit 32 of FIG. 2 without the electrical circuits andconnections in order to distinctly show the sections A, B, C and D. Forthe purpose of simplicity hereinafter, the "printed flexible circuit"will be referred to as "flexible circuit".

The flexible circuit 32 can be made of multi-layers and as a result, itcan have printed circuits on both side. However, for the purpose ofsimplicity, in this specification, only a one sided flexible circuit isdiscussed.

Referring back to FIG. 3, the printed flexible circuit 32 holds a lowvoltage circuit 34, a high voltage circuit 36, a mechanical encoder 38and an indexing pulse generator 40. In this specification, a low voltagecircuit is defined as a circuit which requires less than 15 volts tooperate and a high voltage circuit is defined as a circuit which handlesvoltages such as 1000 volts. Three conductive lines 42, 44 and 46provide the required power to the low voltage and high voltage circuits34 and 36. Conductive line 42 provides 5 V to both low voltage and highvoltage circuits 34 and 36, conductive line 44 provides ground to bothlow voltage and high voltage circuits 34 and 36 and conductive line 46provides 1000 V to the high voltage circuit 36.

The high voltage circuit 36 comprises multiple high voltage chips 48.Each high voltage chip 48 receives a high voltage such as 1000 volts andprovides several identical high output voltages such as 1000 volts. Eachoutput voltage of each high voltage chip 48 will be connected to anelectrode of a SED roll through a conductive line 50 and an output pin52. For the purpose of simplicity only a limited number of conductivelines 50 are shown. The output pins 52 are the connecting point of theflexible circuit 32 to the electrodes of a SED roll. The conductivelines 50 and the output pins 52 are printed on the flexible circuit 32.The number of output pins are equal to the number of electrodes on a SEDroll.

The mechanical encoder 38 comprises a conductive line 54 and a pluralityof parallel conductive lines 56 which are connected to the conductiveline 54. If a contact such as an electrical brush, which is connected toa power supply, moves over the conductive lines 56 along the conductiveline 54, where it touches the conductive lines 56, it will send in asignal into the conductive line 54 and where it moves into the areas 58which there is no conductive line, the signal in the conductive line 54will be disconnected. Therefore, the conductive line 54 receives pulsesas the electrical brush moves over the conductive lines 56.

Conductive lines 60 and 62 have a similar function to the mechanicalencoder 38. If an electrical brush, which is connected to a powersupply, moves over the conductive line 62 along the conductive line 60,where it touches the conductive line 62, it will send in a signal intothe conductive line 60 and where it moves into the areas 64 which thereis no conductive line, the signal in the conductive line 60 will bedisconnected. The pulse generated by the conductive line 62 is used asan indexing pulse. Since the electrical brushes which move over theconductive lines 56 and 62 carry a low voltage, there will be no brushwear or arcing while the electrical brushes connect to or disconnectfrom the conductive lines 56 and 62.

The low voltage circuit shown as box 34 is built with discrete elements.In the preferred embodiment of this invention, the discrete elements ofthe low voltage circuit 34 and high voltage chips 48 of the high voltagecircuit 36 are surface mounted on the printed flexible circuit 32.However, it should be noted that other mounting methods such as chip onflex or solder bump can replace the surface mount of the disclosedembodiment.

The conductive lines 54 and 60 are connected to the low voltage circuit34 and therefore, the pulses from the conductive lines 54 and 60 will bedelivered to the low voltage circuit 34. The low voltage circuit 34receives the pulses and process them to provide a selection signal onthe conductive line 66. The conductive line 66, which is connected tothe high voltage chips 48, delivers the selection signal to the highvoltage chips 48.

The selection signal on the conductive line 66 selects the proper highvoltage chip 48 and causes the selected high voltage chip 48 to turn onselected outputs to activated only a selected number of the electrodesof a SED roll. It should be noted that for the purpose of simplicity,the selection signal is shown as one line 66. However, the selection ofhigh voltage chips and the selection of the outputs within each chip 48requires more than one signal and the low voltage circuit sends outmultiple selection signals.

For the purpose of connecting the printed flexible circuit 32 to a SEDroll, the flexible circuit 32 will be folded along line 68 in such amanner that the surface E and surface F will be facing away from eachother and the back side G of the flexible circuit 32 will be inside ofthe folded flexible circuit. After the flexible circuit 32 is folded, itwill be rolled into a substantially cylindrical circuit. Hereinafter,for the purpose of simplicity, the "substantially flexible circuit" willbe referred to as "cylindrical circuit". Referring to FIG. 5, in orderto create a cylindrical circuit, the flexible circuit 32 has to berolled in such a manner that sections A and B will be located inside thecylindrical circuit and section C will be outside of the cylindricalshape.

Referring to FIG. 6, the rolled flexible circuit 32 has to be tightenedin order to overlap section D over section H. Once section D is placedover section H, they have to be attached to each other by securing meanssuch as adhesive. After section D is attached to section H, each one ofthe conductive lines 60, 42, 44, 46 and 54 creates a closed loop. Oneach loop, a conductive material such as epoxy will be applied to theseam line to create a conductive loop. Loops 42 and 44 are the input tothe low voltage circuit 34 and high voltage circuit 36 and loop 46 isthe input to the high voltage circuit 36. Next, the rolled flexiblecircuit 32 has to be adjusted to align the edge 72 with the edge 74.Section A of the flexible circuit 32 will be located inside thecylindrical circuit 76. The cylindrical circuit 76 will be secured by asecuring means such as a clip 78.

Once the cylindrical circuit 76 is formed, the output pins 52 of theFIG. 3 will be located inside the cylindrical circuit 76 along the edge80. Referring to FIG. 7, the cylindrical circuit 76 will be slid overthe electrodes 82 of a SED roll 84 in such a manner that only the outputpins 52 (FIG. 6) of the cylindrical circuit 76 will be over the SEDroller 84. Then, the cylindrical circuit 76 will be adjusted to aligneach output pin 52 (FIG. 6) to a corresponding electrode 82. To keep thealignment in place, an O-Ring clamp 86 will be used to apply pressure tothe contact between the output pins 52 and the electrodes 82 of the SEDroll 84. However, this connection is not a sturdy connection.

In order to create a sturdy connection, a spool is designed to hold thecylindrical circuit 76. Referring to FIG. 8, there is shown a spool 90which is a connection means between a SED roll and a cylindricalcircuit. Spool 90 has a cylindrical opening 92 along its axis forreceiving the shaft of a SED roll. The opening 92 is designed to receivethe shaft tightly.

The spool has a slit 94 for receiving section A and grooves 96 on itssurface 98 to receive the high voltage chips 48 of the flexible circuit32 of FIG. 3. The flexible circuit 32 of FIG. 3 will be folded along theline 68 and wrapped around the spool 90 in the same manner as creatingthe cylindrical circuit 76. Prior to wrapping the flexible circuit 32around spool 90, section A has to be placed in slit 94. While theflexible circuit 32 is being wrapped around the spool 90, each highvoltage chip 48 will be placed within its corresponding groove 96.

Referring to FIG. 3 and 6, after the flexible circuit 32 is wrappedaround the spool 90, it will be tightened in order to overlap section Dover section H. Once section D is placed over section H, they have to beattached to each other by securing means such as adhesive. After sectionD is attached to section H, each one of the conductive lines 60, 42, 44,46 and 54 creates a closed loop. On each loop, a conductive materialsuch as epoxy will be applied to the seam line to create a conductiveloop. Loops 42 and 44 are the input to the low voltage circuit 34 andhigh voltage circuit 36 and loop 46 is the input to the high voltagecircuit 36. Then, the rolled flexible circuit 32 has to be adjusted toalign the edge 72 with the edge 74. Next, the flexible circuit 32 has tobe secured to the spool 94 of FIG. 8 by a securing means such as a screwor adhesive.

Referring to both FIGS. 8 and 9, once the flexible circuit 32 is wrappedaround the spool 90, a portion of the flexible circuit 32 which holdsthe output pins 52 will extend beyond the edge of the spool 90 tocontact the electrodes 84 of the SED roll 84. Then, the shaft 100 of SEDroll 84 will be slid into the opening 92 of the spool 90 until surface102 of the spool 90 touches surface 104 of the SED roll 84. Spool 90 canbe secured to SED roll 84 by any well known mechanical lock. The spool90 can be designed in such a manner that once it is locked onto the SEDroll 84, the output pins 52 of the wrapped flexible circuit 32 will bealigned and have contact with their corresponding electrodes 82. It isimmaterial if the flexible circuit 32 is wrapped around the spool 90 andconnected to the SED roll 84 or the spool 90 is connected to the SEDroll 84 and then the flexible circuit 32 is wrapped around the spool 90.

In order to provide a better connection between the output pins 52 ofthe flexible circuit 32 and the electrodes 82, an O-ring 106 will beplaced over the flexible circuit 32 over the output pins 52. The O-ring106 will apply pressure to the output pins 52 and keep them secured andaligned with their corresponding electrodes 82 while the SED roll 84rotates.

It should be noted that the O-ring 106 can be replaced by any means thatcan provide the same function. For example, the flexible circuit 32 canbe connected to the SED roll 84 by a conductive adhesive or soldering.

The enclosed embodiment of this invention eliminates the electricalbrush 20 of FIG. 2, but it requires different electrical brushes toprovide power to the flexible circuit 32. It should be noted that theelectrical brushes used in this invention will have a longer life spanand they last much longer than electrical brush 20 of FIG. 2. The designof the enclosed embodiment of this invention provides a solution toelongate the life span of each electrical brush.

Referring to FIG. 10, once the cylindrical circuit 76 is connected tothe SED roll 82, three electrical brushes 110, 112 and 114 will providethe power to the flexible circuit 32. Electrical brush 110, whichcontacts the conductive line (loop) 42, provides 5 volts. Electricalbrush 112, which contacts the conductive line (loop) 44, is for theground. Electrical brush 114, which contacts the conductive line (loop)46 provides 1000 V. In the same manner the, two electrical brush 116 and118 create the required pulses on the mechanical encoder 38 and theindexing pulse generator 40.

In this invention as the SED roll rotates, the electrical brushes have acontinuous contact with their respective conductive line and therefore,they do not cause any spark. This eliminates the arcing problem andprovides a longer life span for the electrical brushes used in thisinvention.

The indexing pulse generator 40 creates a pulse to indicate eachrotation of the SED roll 84. Since there is only one conductive line 62connected to conductive line 60, only one pulse per rotation will begenerated which will be the index for the rotation of the SED roll 84.In the same manner, the mechanical encoder 38 creates pulses as the SEDroll rotates. The number of the pulses generated by the mechanicalencoder 38, during each rotation of the SED roll 84, is proportional tothe number of electrodes 82 of the SED roll 84.

Referring to FIG. 11, there is shown an alternative embodiment of thisinvention which provides a better electrical connection. Flexiblecircuit 130 comprises a low voltage circuit 132 and a high voltagecircuit 134 which are connected to each other in the same manner as thelow voltage circuit 34 and the high voltage circuit 36 of FIG. 3.Furthermore, the low voltage circuit 132 and the high voltage circuit134 are the same and serve the same function as the low voltage circuit34 and the high voltage circuit 36 of FIG. 3. For the purpose ofsimplicity, the details of the high voltage circuit 134 is not shown.However, the output pins 136 and a few of the conductive lines 138 whichconnect the outputs of the high voltage circuit 134 to the output pins136 are shown.

In FIG. 11, the mechanical encoder 38 of FIG. 3 and the indexing pulsegenerator 40 of FIG. 3 are removed. Also in FIG. 11, the conductivelines 142, 144 and 146, which are the same as conductive lines 42, 44and 46 of FIG. 3 respectively, are shortened. Each one of the conductivelines 142, 144 and 146 is connected to a conductive input plate 152, 154and 156 respectively. Conductive lines 158 and 160, which are connectedto the low voltage circuit 132, are also connected to conductive inputplates 162 and 164 respectively. Hereinafter, for the purpose ofsimplicity, the "conductive input plates" will be referred to as "inputplates".

Input plate 162 receives an indexing pulse from an external source andinput plate 164 receives the required pulses from an external encoder.Likewise, input plates 152 and 156 receive 5 volts and 1000 voltsrespectively from external sources and input plate 154 connects to anexternal ground. The connection of the plates 152, 154, 156, 162 and 164to the external sources will be described in a great detail hereinafter.

Referring to FIG. 12, there is shown the flexible circuit 130 of FIG. 11being folded, wrapped around a spool (not shown) to create a cylindricalcircuit 170 which is connected to a SED roll 172. An O-ring 174 securesthe connection of the cylindrical circuit 170 to the SED roll 172.

Referring to FIG. 13, there is shown a slip ring barrel 180. Slip ringbarrel 180 is molded to create a smooth cylindrical surface. The slipring barrel is molded by In-Mold Circuit definition (Two- Shot) processof Mitsui-Pathtek Company. In this process, a non-catalytic resin isinjected in a mold which defines the circuit traces. Once the non-catalytic resin is molded and is taken out of the mold, it has groovesfor the traces of the circuit both on the outer surface and the innersurface of the barrel.

Next, the barrel will be placed in another mold and a plateablecatalytic resin will be injected into the mold to fill in the grooves onthe inner surface and outer surface of the barrel. At this point, thebarrel will be taken out of the second mold and will be chemicallytreated to enhance the plateability of the catalytic resin. The chemicaltreatment roughens the surface of the catalytic resin to createmicropores, which function as anchor sites for plating.

On the last step, the barrel will be copper plated to a specificthickness. The copper plating adheres only to the catalytic resin whichis located in the grooves of the barrel. Therefore, the copper platingwill be located on the traces of the circuit on the outer surface andthe inner surface of the barrel to create conductive lines of thebarrel.

It should be noted that any process which can create the slip ringbarrel 180 of this invention can replace the process of Mitsui-Pathtek.

Referring to FIG. 13, each one of conductive lines 182, 184, 186, 188and 190 on the outer surface 192 of the slip ring barrel 180 creates aclosed loop on the slip ring barrel 180. A plurality of parallelconductive lines 194 are connected to the conductive line 190 to createa mechanical encoder 195 and a conductive line 196 is connected to theconductive line 182 to create an indexing pulse generator 197.

Each conductive line 182, 184, 186, 188 and 190 has a hole 198, 200,202, 204 and 206 respectively to provide an opening into the innersurface 208. The holes 198, 200, 202, 204 and 206 were created throughthe molding of the non-catalytic resin. During the injection of thecatalytic resin a layer of catalytic resin was placed on the walls ofthe holes. As a result, during the copper plating step, a layer ofcopper was adhered to the walls of the holes 198, 200, 202, 204 and 206.Therefore, the holes 198, 200, 202, 204 and 206 provide electricalconnection between the outer surface 192 and the inner surface 208 ofthe barrel 180.

Referring to FIG. 14, there is shown a cross sectional view of FIG. 13along plane 14. FIG. 14 shows the inner surface 208 of the slip ringbarrel 180. Each one of the holes 198, 200, 202, 204 and 206 isconnected to a conductive plate 228, 226, 224, 222 and 220 respectivelythrough a conductive line 220, 222, 224, 226 and 228 respectively.

The holes 198, 200, 202, 204 and 206 provide electrical connection fromconductive lines 182, 184, 186, 188 and 190 on the surface 192 (FIG. 13)to the conductive lines 228, 226, 224, 222 and 220 on the inner surface208 respectively.

Referring to FIG. 15, there is shown the slip ring barrel 180 being slidover the cylindrical circuit 170 of FIG. 12. Once, the slip ring barrel180 is completely over the cylindrical circuit 170, then it has to beadjusted to align the conductive plates 218, 216, 214, 212 and 210 ofthe inner surface 208 with the input plates 162, 152, 154, 156 and 164respectively. The slip ring barrel 180 will be locked onto thecylindrical circuit 170 by any well known mechanical lock. Themechanical lock can be designed to align the input plates 162, 152, 154,156 and 164 to the conductive plates 218, 216, 214, 212 and 210respectively.

In addition, spool 230, around which the cylindrical circuit 170 iswrapped, has a plurality of springs (not shown) each of which is locatedunder one of the input plates 162, 152, 154, 156 and 164 of thecylindrical circuit 170. The springs will push the input plates 162,152, 154, 156 and 164 against the conductive plates 218, 216, 214, 212and 210 of the slip ring barrel respectively to provide a firmconnection.

Referring to FIG. 16, there is shown the slip ring barrel of FIG. 15which is completely slid over the cylindrical circuit 170. Once the slipring barrel 180 is placed over the cylindrical circuit 170, electricalbrushes 232, 234 and 236 will provide the power to the cylindricalcircuit 170. Electrical brush 232, which contacts the conductive line(loop) 184, provides 5 volts. Electrical brush 234, which contacts theconductive line (loop) 186, is for the ground. Electrical brush 236,which contacts the conductive line (loop) 188 provides 1000 V. In thesame manner, the two electrical brush 240 and 238 create pulses on themechanical encoder 195 and the indexing pulse generator 197respectively.

It should be noted that in this invention, depending on the requirementsof the high voltage circuit and low voltage circuit, the number ofelectrical brushes can change.

It should also be noted that in the disclosed embodiments of thisinvention, the SED roll, the cylindrical circuit and the slip ringbarrel are disclosed to have cylindrical or substantially cylindricalshapes. However, the SED roll, the cylindrical circuit and the slip ringbarrel need not be limited to cylindrical shapes.

It should further be noted that numerous changes in details ofconstruction and the combination and arrangement of elements may beresorted to without departing from the true spirit and scope of theinvention as hereinafter claimed.

We claim:
 1. A combination of an electrical circuit with an elongatedmember comprising;an elongated member having an outer surface, a firstaxial end and a second axial end; an elongated hollow element having anouter surface, an inner surface, a first axial end and a second axialend; said elongated hollow element having an electrical circuit; saidelectrical circuit comprising a low voltage circuit and a high voltagecircuit electrically connected to each other; said electrical circuithaving a plurality of input terminals and a plurality of outputterminals; at least one of said plurality of input terminals beingelectrically connected to said high voltage circuit; the remainingterminals of said plurality of input terminals being electricallyconnected to said low voltage circuit and said high voltage circuit;said plurality of output terminals being electrically connected to saidhigh voltage circuit; said plurality of output terminals being locatedon said inner surface of said element at said first axial end of saidelement; said elongated member having a plurality of electricalconductors on said outer surface extending to said first axial end ofsaid first elongated member; said inner surface of said elongated memberat said first axial end of said element partially receiving said outersurface of said elongated member and surrounding said elongated memberat said first axial end of said elongated member; and each one of saidplurality of output terminals having a contact with a corresponding oneof said plurality of electrical conductors of said elongated member. 2.The combination of an electrical circuit with an elongated memberrecited in claim 1, wherein said elongated member is a SED roll of asegmented electrode development unit.
 3. The combination of anelectrical circuit with an elongated member recited in claim 1, whereinsaid element is a substantially cylindrical circuit.
 4. The combinationof an electrical circuit with an elongated member recited in claim 3,wherein said substantially cylindrical circuit is a printed flexiblecircuit.
 5. The combination of an electrical circuit with an elongatedmember recited in claim 3, wherein said inner surface of said element isone piece and said outer surface of said element is another piececonnected to each other on said second axial end of said substantiallycylindrical circuit.
 6. The combination of an electrical circuit with anelongated member recited in claim 5, wherein said elongated member is aSED roll of a segmented electrode development unit.
 7. The combinationof an electrical circuit with an elongated member recited in claim 6,wherein said low voltage circuit, said high voltage circuit and saidplurality of output terminals are located on said inner surface of saidelement and said input terminals are located on said outer surface ofsaid element.
 8. The combination of an electrical circuit with anelongated member recited in claim 7, wherein said high voltage circuitfurther comprises a plurality of high voltage chips.
 9. The combinationof an electrical circuit with an elongated member recited in claim 8,wherein said substantially cylindrical circuit is a printed flexiblecircuit.
 10. The combination of an electrical circuit with an elongatedmember recited in claim 6, wherein said substantially cylindricalcircuit further comprises a mechanical encoder and an indexing pulsegenerator.
 11. The combination of an electrical circuit with anelongated member recited in claim 10, wherein said mechanical encoderfurther comprises a plurality of parallel conductive lines which have afirst end and a second end and said first end of said plurality ofconductive lines being electrically connected to one conductive line.12. The combination of an electrical circuit with an elongated memberrecited in claim 11, wherein said plurality of parallel conductive linesand said one conductive line being located on said outer surface of saidsubstantially cylindrical circuit.
 13. The combination of an electricalcircuit with an elongated member recited in claim 12, wherein saidsubstantially cylindrical circuit is a printed flexible circuit.
 14. Thecombination of an electrical circuit with an elongated member recited inclaim 10, wherein said indexing pulse generator further comprises afirst conductive line which has a first end and a second end and saidfirst end of said first conductive line being electrically connected toa second conductive line.
 15. The combination of an electrical circuitwith an elongated member recited in claim 14, wherein said firstconductive line and said second conductive line of said indexing pulsegenerator being located on said outer surface of said substantiallycylindrical circuit.
 16. The combination of an electrical circuit withan elongated member recited in claim 15, wherein said substantiallycylindrical circuit is a printed flexible circuit.
 17. The combinationof an electrical circuit with an elongated member recited in claim 1,wherein said low voltage circuit and said high voltage circuit arelocated on said inner surface of said element and input terminals beinglocated on said outer surface of said element.
 18. The combination of anelectrical circuit with an elongated member recited in claim 17, whereinsaid high voltage circuit further comprises a plurality of high voltagechips.
 19. The combination of an electrical circuit with an elongatedmember recited in claim 1, wherein said element further comprises amechanical encoder and an indexing pulse generator.
 20. The combinationof an electrical circuit with an elongated member recited in claim 19,wherein said mechanical encoder further comprises a plurality ofparallel conductive lines which have a first end and a second end andsaid first end of said plurality of conductive lines being electricallyconnected to one conductive line.
 21. The combination of an electricalcircuit with an elongated member recited in claim 20, wherein saidplurality of parallel conductive lines and said one conductive linebeing located on said outer surface of said element.
 22. The combinationof an electrical circuit with an elongated member recited in claim 19,wherein said indexing pulse generator further comprises a firstconductive line which has a first end and a second end and said firstend of said first conductive line being electrically connected to asecond conductive line.
 23. The combination of an electrical circuitwith an elongated member recited in claim 22, wherein said firstconductive line and said second conductive line of said indexing pulsegenerator being located on said outer surface of said element.